SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d9bff7d13fb8fcbd248c0105032a2452430c74e1cc50ae77d7a21957ea43eb6' 
  AND token = 'JDqGFxnx5tB+flIuLN1Gk2ZbicX1CppFclx77pZyBTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}